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  <h1>Go 笔记: md5 sum </h1>
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  <div class="span8">
    <p>使用 Go 语言实现字符串与文件的 MD5 值计算，但是大文件不要使用此方法。</p>

<pre><code class="language-go">package utils

import (
	&quot;crypto/md5&quot;
	&quot;io/ioutil&quot;
	&quot;strconv&quot;
)

const (
	MD5_STR_LEN = 32
)

func md5ByteToStr(bytes [16]byte) string {
	str := &quot;&quot;

	for _, b := range bytes {
		s := strconv.FormatInt(int64(b), 16)
		if len(s) == 1 {
			str += &quot;0&quot; + s
		} else {
			str += s
		}
	}

	return str
}

func SumStrMd5(str string) (string, bool) {
	if len(str) &lt; 1 {
		return &quot;&quot;, false
	}

	md5Byte := md5.Sum([]byte(str))
	md5Str := md5ByteToStr(md5Byte)
	if len(md5Str) &lt; MD5_STR_LEN {
		return &quot;&quot;, false
	}

	return md5Str, true
}

func SumFileMd5(filename string) (string, bool) {
	if !IsFileExist(filename) {
		return &quot;&quot;, false
	}

	contents, err := ioutil.ReadFile(filename)
	if err != nil {
		return &quot;&quot;, false
	}

	md5Byte := md5.Sum(contents)
	md5Str := md5ByteToStr(md5Byte)
	if len(md5Str) &lt; MD5_STR_LEN {
		return &quot;&quot;, false
	}

	return md5Str, true
}
</code></pre>

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  <div class="span4">
    <h4>Published</h4>
    <div class="date"><span>2014-06-22 22:54:38</span></div>
    <br>
    <h4>Categories</h4>
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  <a href="/categories/#Note-ref">Note <span>9</span></a>
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    <h4>Tags</h4>
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  <a href="/tags/#go-ref">go <span>6</span></a>
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  <a href="/tags/#md5-ref">md5 <span>1</span></a>
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